PCSK1 and type 2 diabetes mellitus: Here, gene-specific gradient fields for increasing expression align with known disease axes: genes downregulated in T2D for β-cells (Ins1, Pcsk1, Mdh1, Aldoa) point from diabetic to normal β-cell regions, whereas genes upregulated in T2D for α-cells (Pcsk2, Gcg) and stress/metabolic markers (Acot7, Fabp5) point from normal toward diabetic regions.